How to use the command 'next' (with examples)

Next.js is a React framework that uses server-side rendering to build optimized web applications. This article will guide you on how to use the next command for various use cases.

Use case 1: Start the current application in development mode

Code:

next dev

Motivation: This command is used to start the current application in development mode. It is useful when you are working on a Next.js project and want to preview the changes locally.

Explanation:

• next: The main command to run Next.js applications.
• dev: The subcommand to start the application in development mode.

Example output:

ready on http://localhost:3000

Use case 2: Start the current application and listen on a specific port

Code:

next dev --port port

Motivation: There might be cases where you want to start the application on a specific port. This command allows you to specify the port number, giving you more control over the configuration.

Explanation:

• next: The main command to run Next.js applications.
• dev: The subcommand to start the application in development mode.
• --port port: The --port option allows you to specify the port number on which the application should listen.

Example output:

ready on http://localhost:8080

Use case 3: Build the current application optimized for production

Code:

next build

Motivation: Before deploying your Next.js application to a production environment, you need to build it to optimize performance and bundle the necessary assets. This command is used to build the application for production.

Explanation:

• next: The main command to run Next.js applications.
• build: The subcommand to build the application for production.

Example output:

Creating an optimized production build...

Use case 4: Start the compiled application in production mode

Code:

next start

Motivation: After building the Next.js application for production, you can use this command to start the compiled application. It allows you to test and run the optimized version of your application locally.

Explanation:

• next: The main command to run Next.js applications.
• start: The subcommand to start the compiled application in production mode.

Example output:

ready on http://localhost:3000

Use case 5: Start the compiled application and listen on a specific port

Code:

next start --port port

Motivation: Similar to the previous use case, this command is used to start the compiled application in production mode but on a specific port. It gives you the flexibility to choose the port number for your application.

Explanation:

• next: The main command to run Next.js applications.
• start: The subcommand to start the compiled application in production mode.
• --port port: The --port option allows you to specify the port number on which the application should listen.

Example output:

ready on http://localhost:8080

Use case 6: Export the current application to static HTML pages

Code:

next export

Motivation: Sometimes, instead of serving your Next.js application from a server, you may want to export it as static HTML pages which can be hosted anywhere, even on a static file hosting service. This command allows you to export the application as static HTML pages.

Explanation:

• next: The main command to run Next.js applications.
• export: The subcommand to export the application to static HTML pages.

Example output:

Exporting to ./out...
Export successful. Don't forget to run a static server.

Use case 7: Display the Next.js telemetry status

Code:

next telemetry

Motivation: Next.js provides telemetry to help improve their framework. This command displays the telemetry status, giving you an insight into the data collection and usage by Next.js.

Explanation:

• next: The main command to run Next.js applications.
• telemetry: The subcommand to display the Next.js telemetry status.

Example output:

Telemetry is enabled by default in Next.js.

Use case 8: Display help for a subcommand

Code:

next build|dev|export|start|telemetry --help

Motivation: If you are not sure about how to use a specific subcommand of the next command, you can use this command to display detailed help and documentation for that subcommand.

Explanation:

• next: The main command to run Next.js applications.
• build|dev|export|start|telemetry: The specific subcommand for which you want to display the help.
• --help: The option to display help and documentation for the specified subcommand.

Example output:

Usage: next build|dev|export|start|telemetry --help
Options:
...
  -h, --help     display usage information

Conclusion

The next command provides a wide range of functionalities for developing, building, and maintaining Next.js applications. Whether you are starting your application in development mode, building for production, or exporting as static HTML pages, the next command has got you covered. Additionally, it allows you to customize the port number and gain insights into Next.js telemetry. Use the provided examples and explanations to leverage the power of the next command in your Next.js projects.